| Eh, a bit overstated. None of them killed EVERYTHING, near as we can tell. Not even the oxygen catastrophe you're mentioning. To do that would likely require liquifying the mantle entirely, or some similar scale event. The last big one was approximately 66 million years ago due to perhaps the Chicxulub impact, and it wiped out most of the dinosaurs - but modern birds are descended from them, and the crocodiles and alligators survived (well, VERY similar looking ancestors) /just fine. None of them could build space stations, nuclear reactors, bunkers, etc. That we know of at least. None of them could grow hydroponic food, or communicate at near light speed to the other side of the planet, or even know what any of that means. The entire span of time something vaguely resembling human has been around is also 1/10th of that time, but there have been MANY smaller events with large scale extinctions. I'm not saying it would be a good time, but there is no way every single human is getting wiped out by anything except a nearby Gamma Ray burst/Supernova, surprise planetary collision, or something of similar destructive scale. Things way beyond even our wildest dreams of destructive power. Even if we launched every nuke every country has ever produced, while civilization as we know it would be done for, humanity would definitely persist. Even if the next war would be fought with clubs instead of nukes. And even if all the oxygen in the atmosphere turned to cyanide - guess what, we do (technically) know how to deal with that, there are populations of people who are currently protected from that, and while most of humanity would die while we scrambled to adapt, humanity itself would not perish. At least not just from that. |